Partly inspired by @amfas’s video about the minijack patch bay, I made a very simple patch bay for composite video. It uses mini jack for patching but has RCA connectors for inputs and outputs. It doesn’t have any normalling, so what you patch is what you get.
It’s open source and made in KiCad, so feel free to fork, improve it and change it to your needs. Pull requests welcome!
I like it. If you moved the VP Buddy logo to the bottom you’d have more space along the top to increase the white area, plus the logo would remain visible while fully patched. Cheers.
Good point, thanks! I’ll keep it in mind for the next version.
this patch bay looks great !
never tried using one my self but am tempted to try making one of these :))
Thanks! It’s already proven itself very useful to me. I keep forgetting which devices are connected and having all the connections right in front of me helps a lot. Also changing connections doesn’t involve untangling that rat’s nest of RCA cables anymore.
That looks great!
I got a pile of free music ear from someone a couple of years ago and one of the things in it was an old Tascam 32 point RCA patchbay with switched RCA jacks, so it’s normalled like a regualr audio patchbay. It’s kind of hard to find switching RCA jacks these days (I don’t think anyone makes them now but new old stock isn’t very expensive; I’ve got a couple dozen of these Switchcrafts and they’re really nice). It would be super useful to add pads and traces that would let people who wanted to use these Switchcrafts instead of conventional RCA jacks. Having a because normalled (or half normalled) composite patchbay is one of the best additions I’ve made to my setup and I can’t recommend it highly enough.
Not sure if I’ll ever be able to do it myself, I’ve only done veroboard layouts and don’t really have the time to learn PCB layout software right now (especially since I already have an RCA patchbay) but I could definitely take some measurements and photos of the jacks if anyone is interested. Since they’re panel mount, it wouldn’t have to be too accurate (and maybe the best way would be to add traces for normalling, a simple header, and an alternate panel that had space to mount them. That way anyone who wanted to make a normalled version could source the jacks, wire them up to the header, mount them on the alternate front panel and be all set.
Wow, I didn’t even know switching RCA jacks existed!
The mini jacks I’m using are switching, I’m just not using the switching feature for VP Buddy. So you could activate normalling by connecting the two currently unused switching pins of the mini jacks with a wire. I just did this on one of my PCBs and it works great. With the wire in place the top and bottom RCA jacks are always connected, inserting a cable in one of the mini jack sockets breaks the connection.
(red = PCB traces, green = wire)
I think for the next version I will add dip switches to make it possible to activate normalling per channel.
I didn’t either until about a year ago.
I’m pretty sure Switchcraft stopped making them in the 80s but I can’t remember where I got that idea so don’t take my word for it!
What’s the normaling function? How does it affect the signal?
It’s the same as one of the inexpensive 1/4" normalled patchbays that have cards for each channel that you can reorient to change the normalling behavior. Every channel I’ve used on this one is set for full normal, which is what I needed. I doesn’t affect the signal any more than a cable does, but I haven’t tried using it as a passive splitter in half-normal configuration.
EDIT: that’s in the Tascam. I’ve never used the Switchcrafts for video. In fact, I only needed one to add a footswitch for the negative feedback mod I added to my homemade guitar amp, but it rutned out they didn’t work because it needs a jack that’s fully isolated from the chassis, so I had to use a 1/4" instead. The minimum order was 25 so I still have 24 of them plus the one I used.
Cool project. As well as being able to switch routing about easily it opens up other possibilties too.
The 0hp ST modular passive workmate ‘swap’ module could be used to instantly switch some routings around with a press of the toggle switch.
I’m wondering what effect would an LDR have on a video signal ? Would it switch on and off when light was applied like it does with an audio signal ? If so the passive ‘Eye tenuator’ from mystic circuits could also be used with the VP buddy…